Germany’s foreign intelligence agency officially lifted the lid on some of its worst-kept secrets on Friday, acknowledging that half a dozen facilities around the country are in fact spy stations — as anyone with Internet access could already figure out.

The Federal Intelligence Service, known by its German acronym BND, maintained the facade for decades that it had nothing to do with sites bearing cryptic names such as ‘‘Ionosphere Institute.’’ But amateur sleuths long suspected their true identities and posted them on websites such as Wikipedia.

The subterfuge wasn’t helped by the fact that some sites sport unmistakable signs of spy activity, like the giant golf ball-shaped radomes in Bad Aibling, near Munich — until now, the ‘‘Telecommunications Traffic Office of the German Armed Forces.’’

The agency officially attached its logo to the site’s entrance at a ceremony Friday, and BND chief Gerhard Schindler posed for photographers in front of the radomes.

The rebranding is part of an effort by Schindler to make the work of Germany’s spies more transparent. The agency has sought to distance itself from some of its counterparts following Edward Snowden’s revelations about the US National Security Agency, insisting it follows the law and doesn’t conduct unwarranted mass surveillance.

‘‘It makes no sense, to give a simple example, that external sites of the BND are run with covert names if the fact that they belong to the BND can be read on the Internet,’’ Schindler acknowledged in a public speech last year.

‘‘If there’s one thing that the man on the street will remember from the whole NSA debate in Germany, it’s that the satellite ground stations in Bad Aibling belong to the BND,’’ he added.

The six sites now officially acknowledged are mostly linked to the agency’s signals intelligence work — jargon for eavesdropping on radio, data and phone traffic.

Earlier this year Schindler opened the BND’s huge new Berlin headquarters, complete with a visitors’ center.